In traditional physical networking, routes come in three types—connected, static, and dynamic. Connected routes are those determined automatically based on local interface information. When an interface has an address configured in a subnet, then the router has a directly connected route to that subnet. Static routes are those manually configured at the router, and dynamic routes are learned from other routers via routing protocols (e.g., BGP, OSPF, IGP, etc.). As this may result in a router being presented with multiple routes for the same IP address, routers perform various processing techniques in order to choose between these routes.
Virtual networks may also have routers, referred to as logical routers. Previous implementations of logical routers have only used connected routes, however, generated based on the IP prefix configured on the port of the logical router. Adding different types of routes to logical routers would pose the problem of requiring additional processing techniques for the logical routers, which may not be easily performed by the software forwarding elements often used to implement such logical routers.